This invention relates to a stone saw comprising a revolving sawing rope, which is backed against the cutting pressure by backing rollers at both ends of at least one sawing portion, also comprising a feed drive and housings in which the backing rollers are mounted and which are pivotally adjustable about the axis of the sawing rope in dependence on the direction of the feed movement.
In such stone saws, which are known from AT-B- No. 371,761, the pivotal adjustment of the backing rollers about the axis of the sawing rope has the result that the forces which are exerted on the backing rollers owing to the cutting pressures applied will be at right angles to the axes of rotation of said rollers so that the side faces of the rope-guiding groove of the backing roller will not be subjected to substantial loads. This ensures that the wear of the rope-guiding grooves will be minimized and the rope will be exactly guided even after a prolonged operation.
Whereas such a guidance of the rope is necessary for an exact contour sawing it is not adequate for that purpose. For an exact control of the direction of the cut, the axis of rotation of each of the housings in which the backing rollers are mounted must coincide with the axis of the sawing rope. The inevitable wear of the rope-guiding grooves will result in a shift of the axis of the sawing rope relative to the structurally defined axis of rotation of the housing so that, e.g., curves having a small radius of curvature can no longer be cut as exactly as is required.